A steel 4-bolt center main cap is the best way to counteract the flexing of the Mini's 3-main bearing crank. We've been running this Fortech design steel cap for 20 years without problems. The two outer bolts (included) are 7/16", and no thrust washer is cut into the cap. This cuts down on machining costs necessary to align the thrust surfaces. While this reduces the thrust bearing surface by half, it is acceptable in a competition or performance engine when the driver should know not to ride the clutch.
Fits all 1300 A-Plus or Austin America blocks. Line-boring required to install.